VINCENT SAV-C2 Manuel D'utilisation page 39

Composite Video, FBAS
Video signal format very similar to the PAL television
signal, using the YUV colour model. It actually com-
prises three signals, which can be transmitted over
a single cable due to technical tricks. These three
component signals are the YUV signals derived from
the Red/Green/Blue (RGB) portions of a video rec-
ording. 75Ω coaxial cables are used for the trans-
mission, the terminal box is generally a RCA socke
labelled "Video". Plug and socket are generally
marked yellow. The picture quality with the use of
other signal standards (Component Video, S-Video,
HDI, HDMI,...) is almost always better.
S-Video
An analogue video signal standard, which trans-
mits what is called a Y/C signal. The brightness
signal Y (Luminance) and the colour signal C
(Chrominance) are transmitted via two separate
cables. Most home-cinema components support this
type of signal. It provides greater picture quality
than the Composite Signal, but is superseded by
the Component Signal. The associated terminal box
on AV units is often labelled "S-VIDEO" or "Y/C".
The S-Video Y/C signal can either be fed via a
Mini-DIN (Hosiden) socket or via the SCART con-
nection. The S-Video signal is always output in the
"Interlaced Scan" mode, Progressive Scan is im-
possible (in this setting the output is switched off).
The picture quality achieved depends on the quali-
ty of the cable used. This transmission system is
often also wrongly called S-VHS transmission.
Component Video
Alternative signal presentation form for colour video
signals calculated from the RGB format. Here, too,
three individual signals are used together, but are
not separated are "Red, "Green" and "Blue" inten-
sity signals, but as one brightness signal Y and two
colour difference signals. The YUV (used for the PAL
signal, Composite Video signal and S-Video), YIQ
(used for NTSC signals), YPbPr (used for the video
component signal in hi-fi electronics) and YCbCr
(digital colour video signal standard corresponding
to the analogue YPbPr) formats are distinguished
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GLOSSARY
dependent on the calculation formulae in respect of
RGB. However, the designation "Component
Video" generally means the YPbPr standard.
YUV
An analogue standard for the presentation of a
colour video signal used for different analogue video
transmission standards. It describes the representati-
on of the video signal using three signal components,
very similar to the signal components used for YPbPr.
This standard is applied to PAL-TV, Composite Video
and S-Video. As part of this, the individual signals
can be transmitted over one line (the UV signal modu-
lated to a carrier frequency, as with Composite
Video) or separated over two lines (as with S-Video).
The three components are firstly the brightness signal
(Y), a difference signal between the brightness signal
and the signal of the blue portion (U) and a diffe-
rence signal between the brightness signal and the
signal of the red portion (V). These components can
be derived and converted from the RGB or the YPbPr
signal. Advantage: The brightness and the colour
information are transmitted separately.
YPbPr, Component Video
One analogue colour video model used for
Component Video. It is similar to the YUV colour
model used for Composite Video, only different
coefficients are used in the calculation of the colour
difference signals from the RGB colour video
model. The three components are firstly the bright-
ness signal (Y), a difference signal between the
brightness signal and the signal of the blue portion
(Pb) and a difference signal between the brightness
signal and the signal of the red portion (Pr).
Advantage: The brightness and the colour informa-
tion are transmitted separately. The YPbPr and RGB
standards merge (convert) into each other easily.
The three individual signals are generally transmit-
ted via three RCA connections. YPbPr signals can
contain video information either line-wise in full
images (Progressive Scan) or line-wise in half-
images (Interlaced Scan).
GLOSSARY
YCbCr, Digital Component Video
The digital colour video model used for Component
Video. A digital representation of the YPbPr stan-
dard. It is transmitted in a digital data stream via a
cable or a line in a loom of cables (DVI, HDMI).
MPEG videos (as used on the DVD) are stored in
digital component form (YCbCr), on playback they
can be converted to analogue and output via the
YPbPr outputs or via digital interfaces (DVI, HDMI)
without conversion.
Surround sound
Enhancement of the conventional stereo technology,
a Surround system produces stereophonic effects,
which give the listener the impression of being in
the middle of events. The "live" experience begins
if the sound seems to come from a direction that the
video scene suggests. Surround sound systems
solve this problem by multi-channel sound transmis-
sion; it is not two (right and left) sound signals that
are stored and played back, but four or more.
These are then played by four or more speakers
arranged around the listener. However, there are
analogue as well as digital surround sound
systems. As mentioned above, the superior-sound
digital variant not only has more channels, but the
data required for stereophonic sound are also sto-
red in digital format. Digital formats therefore
spread mainly on DVD's, CD's or on digital televisi-
on. Analogue formats are found on videocassettes
and in analogue television signals. Each standard
in the home-cinema range requires a specific deco-
der and some formats are compatible with each
other.
Dolby
A company located in the Bay area near San
Francisco (Dolby Laboratories, Inc), named after its
founder and president Ray Dolby. In the recent
decades this company developed many technolo-
gies and signal processing standards for the impro-
vement of audio playback and recording. Most
famous products are „Dolby NR" (noise reduction
for audio tape playback), „Dolby Surround
Prologic" (analog multi channel audio standard)
and „Dolby Digital" (digital multi channel audio
standard).
Dolby Surround Prologic
Dolby Prologic is an analog four-channel audio
system including two front channels, one Center
channel and one Surround channel. The signals of
both additional channels are integrated in a clever
way into the Stereo signal (of VHS-Cassettes, LD's
und DVD's, as well as diverse TV programmes), so
that even conventional equipment, that cannot pro-
cess surround sound, can use the integrated stereo
sound as usual. A decoder separates the four chan-
nels. The Dolby Surround Prologic sound quality is
not perfect: the surround channel is monophonic
and has a cut frequency range of 100 to 7000 Hz.
Moreover, as opposed to the digital surround
systems a considerable crosstalk into both additio-
nal channels is present.
Dolby Prologic II (5.1)
From conventional two channel signals, for exam-
ple digital PCM, analogue Stereo or Dolby
Surround Prologic signals 5.1 separate channelsa-
re calculated. All Dolby Surround software offered
up to now contains decoders for Prologic II. As
opposed to Prologic the full HiFi frequency range is
covered for all channels and there are two surround
channels.
Dolby Digital 5.1 (AC-3)
Dolby Digital 5.1 (firstly named AC-3) is a digital
audio multi channel format developed in 1992 for
the movie sound recording and playback in the
Dolby Laboratories. It contains up to six indepen-
dent channels (two front channels, one center chan-
nel, two surround channels and one low-frequency
channel (LFE)). The first mentioned five channels can
transfer the full audible frequency range (20 to
20,000 Hz), the LFE channel only the low bass fre-
quency range (20 bis 120 Hz). All separate digital
signals are interleaved into one digital data stream
that can be transferred via ONE digital cable.
Compression techniques are used to reduce the
huge data rate necessary for this high quality signal
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